The field of the disclosure relates generally to electrical power conversion and electrical energy storage systems, and, more specifically, to systems and methods for integrating hybrid energy storage into direct current (DC) power systems.
In at least some known systems and methods for integrating energy storage devices (ESDs) into DC power systems, ESDs such as ultracapacitors positioned in current paths of bi-directional DC-to-alternating current (AC) converters experience undesirable AC ripple currents which degrade ESDs' performance, longevity, and power quality. To increase efficiency of power conversion where ESDs are exposed to AC currents in such known systems and methods, ESDs are over-sized to manage heat, which increases size, weight, and cost in addition to lowering specific power density.
Also, in at least some known systems and methods for integrating ESDs into DC power systems, non-modular topologies such as buck-boost converter architectures are limited in attainable switching frequencies and dynamic responsiveness, and also present challenges related to fault isolation and tolerance. In the event of a fault in such “centralized” power conversion systems and methods, electrical loads supported thereby require shutdown until system repairs are made, and such repairs are costly and time-consuming in at least some known systems and methods, and they may require a complete re-design and re-build of the power converter for affected load devices.